Fast inflating air pump

ABSTRACT

The present invention discloses a fast inflating air pump, including a housing, an inflating tube, an inlet tube, a motor, a transmission assembly and a controller housed in the housing. A blower is arranged in the inlet tube for increasing air pressure to the inflating port. A piston is at least partially contained in the inflating tube, and the piston is driven by the motor via the transmission assembly so as to slide back and forth linearly for increasing air pressure in the inflating tube. A one-way valve is installed in the communicating pipe for only allowing air flow into the inflating tube. The controller instructs the motor to drive the piston to slide back and forth in the inflation tube on condition that the blower stops working until the air inflation pressure increases to a predetermined threshold, then the controller instructs the motor to stop operating.

FIELD OF THE DISCLOSURE

The present disclosure relates to an air pump, and more particularly to a fast electric inflating air pump.

BACKGROUND

The inflating air pump works by an electric motor. The working principle is that the motor pimps air into objects that need to be inflated, such as tires, boat cushions, etc., which can realize the effect of inflation automatically.

Generally, the inflating pump uses a single inflating method, that is, it is driven by a motor to inflate the object to be inflated. As the pressure of the object to be inflated changes before and during the inflation process, as it is inflated, its pressure becomes greater and greater. The single inflation method leads to the defects of low inflation efficiency and long inflation time. In addition, due to the poor airtightness during the inflation process, air leakage occurs, which makes the working efficiency of the inflator pump even lower.

Therefore, it is necessary to provide a fast electric inflating air pump for solving the issues.

SUMMARY OF THE INVENTION

In view of this, the present disclosure is designed to provide a fast electric inflating air pump to solve the problem of low inflation efficiency.

A fast inflating air pump comprises a housing, a controller, a blower, a motor, an inlet tube and an inflating tube are arranged in the housing. The inflating tube includes an inflating port which is exposed on the outside of the housing to communicate with external air. A piston is at least partially received in the inflating tube. The motor drives the piston to linearly slide back and forth in the inflating tube via a transmission assembly. The inflating pipe is communicated with the inlet tube via a communicating pipe. A blower is housed in the inlet tube. A one-way valve is provided in the communicating pipe so that air flows from the communicating pipe to the inflating tube. During the fast inflating air pump is inflating, the controller instructs the blower to operate until an air pressure value reaches a predetermined threshold, and the controller instructs the blower to stop working. At this moment, the controller instructs the motor to drive the piston to move back and forth in the inflating tube to achieve inflation, until the air pressure value increases to another predetermined threshold, then the controller instructs the motor to stop operating.

In another aspect, the inlet tube includes an inlet port which is exposed on the outside of the housing for communicating with external air, and another port is communicated with the communicating pipe.

In another aspect, the inflating tube includes a small-diameter section and a large-diameter section extending from the small-diameter section, the inflation port is formed in the small-diameter section. A diameter of the large-diameter section is larger than that of the small-diameter section. The piston is movably placed in the large-diameter section, and on condition that the controller instructs the motor to drive the piston to move, the piston linearly moves back and forth in the large-diameter section.

In another aspect, the piston includes a head end, a tail end and a piston rod between the head end and the tail end. The transmission assembly includes a gear plate driven by the motor, an eccentric wheel, a rotating shaft located in the center of the gear plate and connected to the eccentric wheel, and a transmission rod located on the eccentric wheel, and the transmission rod is sleeved on the tail end of the piston. The motor drives the gear plate to rotate, and the gear plate drives the head end of the piston to linearly slide back and forth in the inflating tube via the eccentric wheel.

In another aspect, the tail end of the piston has a hole provided in the central area of the tail end, and the transmission rod is at least partially sleeved in the hole.

In another aspect, a frame connected with an inflating tube is arranged in the housing, and the gear plate is supported by the frame.

In another aspect, the gear plate has an external teeth provided on the outer periphery of the gear plate. The motor has a shaft with a transmission gear, the gear plate meshes with the transmission gear of the motor.

In another aspect, the blower is arranged in the inlet tube.

In another aspect, the controller is provided with a controlling circuit for controlling the operation of the air pump, including a power supply, a power switch, a controlling unit and two selecting switches. Each of the two selecting switches has an input terminal connected with the power supply, an output terminal connected with the air pump, a ground terminal, and a controlling terminal connected with the controlling unit. The selecting switch includes a connecting terminal connected to the air pump, and the connecting terminal of the selecting switch is selectively connected to the input terminal or the ground terminal of the selecting switch according to an selecting signal from the controlling unit.

In another aspect, an output terminal of a first selecting switch is connected with the input terminal or the ground terminal of the selecting switch, and an output terminal of a second selecting switch is connected with the ground terminal or the input terminal of the selecting switch correspondingly.

In another aspect, each of the two selecting switches includes two field effect transistors with different conduction potentials. The two field effect transistors define first field effect transistor and a second field effect transistor. A source or a drain of the first field effect transistor severs as the input terminal of the selecting switch. The drain or source of the first field effect transistor is connected to a source or a drain of the second field effect transistor as the output terminal of the selecting switch. The drain or the source of the second field effect transistor serves as the ground terminal of the selecting switch. A grids of the two field effect transistors are connected as the controlling terminal of the selecting switch.

In another aspect, the field effect transistor is defined as an N-channel field effect transistor or a P-channel field effect transistor.

In another aspect, the controller includes a flip-flop and two triodes. A bases of the two triodes are respectively connected to the two output terminals of the flip-flop, a collector of the two triodes are respectively connected to the controlling terminals of the two selecting switches, and a emitter of the two triodes connected with the ground respectively. The flip-flop outputs a high and a low-level signal to make one of the two triodes turn on, and the other turns off.

In another aspect, the flip-flop is a set-reset flip-flop, or a jump-key flip-flop or a D-type flip-flop.

The fast inflating air pump provided by the present disclosure, the controller instructs the blower to restart the rapid inflation, until the inflation pressure reaches a predetermined threshold, then stops the blower, and synchronously instructs the motor to drive the piston to move back and forth to inflate to achieve high pressure inflation. The inflation pressure reaches a predetermined threshold, so that the low pressure and high pressure are sequentially converted to inflate, and the effect of fast inflation can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiment.

FIG. 1 is an isometric view of an inflating air pump in accordance with an exemplary embodiment of the present disclosure, with a part of a housing thereof being removed away.

FIG. 2 is an isometric view of the inflating air pump in FIG. 1, viewed from another aspect, with the housing thereof being removed away.

FIG. 3 is an isometric exploded view of the inflating air pump in FIG. 1.

FIG. 4 is an isometric exploded view of a part of the inflating air pump in FIG. 1.

FIG. 5 depicts an assembled view of a motor and a transmission assembly of the inflating air pump in accordance with an embodiment of the present disclosure.

FIG. 6 is a cross-sectional view of an inflating tube of the inflating air pump in FIG. 1.

FIG. 7 is a schematic diagram of an controlling circuit of the inflating air pump of the present disclosure.

FIG. 8 is a topological structure diagram of the controlling circuit of the inflating air pump in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present disclosure will be described in detail in conjunction with the drawings. It should be noted that the figures are illustrative rather than limiting. The figures are not drawn to scale, do not illustrate every aspect of the described embodiments, and do not limit the scope of the present disclosure.

It should be noted that when a component is considered to be “connected” to another component, it can be directly connected to another component or a central component can be present between two components at the same time. When a component is considered to be “provided” another component, it may be arranged directly on another component or possibly with a centered component.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning, which is used in the description of the present disclosure to describe specific embodiments and is not intended to limit the disclosure. The term “or/and” used here includes any and all combinations of one or more of the associated listed items.

Referring to FIGS. 1-8, a fast inflating air pump according to an embodiment of the present disclosure is shown. The fast inflating air pump comprises a housing 100 having an upper shell 1012 and a lower shell 1011, a controller 800, a blower 501, a motor 400, an inlet tube 203 and an inflating tube are arranged in the housing 100. The inflating tube includes an inflating port 102 which is exposed on the outside of the housing 100 to communicate with external air. A piston is at least partially received in the inflation tube. The piston includes a head end 700, a tail end 702 and a piston rod 701 between the head end 700 and the tail end 702. The motor 400 drives the piston to linearly slide back and forth in the inflating tube via a transmission assembly for increasing air pressure in the inflating tube. During the reciprocating motion cycle, the piston continuously outputs air to the inflating port 102 of the inflating tube, so that the inflating pump outputs air under high pressure.

A communicating pipe 300 is arranged between the inflating tube and the inlet tube 203, and a one-way valve 500 is arranged in the communicating pipe 300. The one-way valve 500 unidirectionally circulates air from the communicating pipe 300 to the inflating pipe. Thus, the blower 501 in the inlet tube 203 drives the air to be discharged through the inflating port 102 of the inflating tube.

During the fast inflating air pump is inflating, the controller 800 instructs the blower 501 to work until an air pressure value reaches a predetermined threshold, and the controller 800 instructs the blower 501 to stop working. At this moment, the controller 800 instructs the motor 400 to drive the piston to move back and forth in the inflating tube to achieve inflation, until the air pressure value increases to another predetermined threshold, then the controller 800 instructs the motor 400 to stop operating.

In order to improve the inflation efficiency, the controller 800 first instructs the blower 501 to rotate to inflate a target object, such as a tire, until an internal air pressure of the inflating air pump reaches a predetermined threshold, and then instructs the blower 501 to stop working. At this moment, the motor 400 is immediately started to drive the piston to slide back and forth to inflate into the inflating tube to achieve inflation under a relatively high pressure state until the air pressure of the inflating pump reaches another predetermined threshold. During this process, the internal air pressure of the inflating air pump is increased from a low air pressure to a relatively high air pressure to achieve the effect of rapid inflation.

In the embodiment, the upper shell 1011 and the lower shell 1012 enclose a housing 100 with a cavity. The housing 100 may also be enclosed by other components, and is not limited to the enclosed manner of the upper shell 1011 and the lower shell 1012 in the present disclosure.

The inlet tube 203 includes an inlet port 101 which is exposed on the outside of the housing 100 for communicating with external air, and another port is communicated with the inflating tube via the communicating pipe 300.

The inflating tube includes a small-diameter section 201 and a large-diameter section 202 extending from the small-diameter section 201, the inflation port 102 is formed in the small-diameter section 201. The terms “large diameter” and “small diameter” here are relative sizes and do not have the concept of actual size. A diameter of the large-diameter section 202 is larger than that of the small-diameter section 201. The piston is movably placed in the large-diameter section 202, and on condition that the controller 800 instructs the motor 400 to drive the piston to move, the piston linearly moves back and forth in the large-diameter section 202.

In the embodiment, the head end 700 of the piston is received in the large-diameter section 202 of the inflating tube. The head end 700 of the piston is in shape of a disc that matches an inner wall of the large-diameter section 202 of the inflating tube, and a plurality of holes 704 are provided in the central area of the disc of the head end 700. A damper 710 is mounted on the disc-shaped head end 700 of the piston. A valve plate 601 is located above the head end 700 in the large diameter portion. The valve plate 601 includes a rigid sheet 602 with a plurality of holes provided in the inflation tube, and a rubber sheet 603 which is attached to the rigid sheet 602 to block the holes so that air can only flow from the head end 700 through the hole into the inflation port 102. The valve plate 601 acts as a one-way valve.

In the embodiment, the head end 700 further has an upper flange 705 on the periphery of the disc, an upper flange 706 on the periphery of the disc and a ring groove 707 between the upper flange 705 and the lower flange 706 for receiving the damper 710. The damper 710 has a central part 711, two bridges 712 extending from the central part 711 along a direction far away each other and an annular wall located on the outer peripheral side of the two bridges 712 and connected to the two bridges 712. The annular wall has an inner wall 713 extending from the two bridges 712, an outer wall 714 extending from the inner wall 713 for sliding contact with the inflating tube, and a groove 715 provided between the inner wall 713 and the outer wall 714. The central part 711 of the damper 710 blocks a plurality of holes 704 of the head end 700 so that air can only flow into the inflating tube. In order to avoid air leakage, two notches 708 are provided on the upper flange 705 for matching the two bridges 712. The two bridges 712 are respectively arranged in the two notches 708 to improve the firmness of the damper 710. An air chamber is formed by the valve plate 601, an head end 700 with the damper 710 and a part of the large-diameter section 202 of the inflating tube. When the piston slides back and forth in the large-diameter section 202, the head end 700 slides along a direction gradually approaching the valve plate 601, and the air in the air chamber can only flow into the small-diameter section 201 through the holes of the valve plate 601. When the head end 700 slides along a direction gradually away from the valve plate 601, the holes of the valve plate 601 is blocked by the rubber sheet 603, and air enters the air chamber through the holes of the head end 700 for balancing air pressure. The rotation speed of the motor 400 may reach 10,000 revolutions per minute. Driven by the high frequency of the motor 400, the piston quickly presses the air in the air chamber into the inflating tube for obtaining high air pressure. This enhances the inflation efficiency of the inflating air pump and can meet higher pressure inflation requirements with the assistance of the blower.

The head end 700 of the piston is received in the large-diameter section 202, and the piston rod 701 is at least partially exposed outside the he large-diameter section 202. The tail end 702 has a ring 402 and a hole provided in the central area of the ring 402. The motor drives the piston by a transmission assembly. The transmission assembly includes a gear plate 410 driven by the motor 400, an eccentric wheel 403, a rotating shaft 411 located in the center of the gear plate 410 and connected to the eccentric wheel 403, and a transmission rod 405 located on the eccentric wheel. The transmission rod 405 is sleeved in the ring 402 of the tail end of the piston. The motor drives the gear plate 410 to rotate, and the gear plate 410 drives the piston to linearly slide back and forth in the inflating tube via the eccentric wheel 403.

In the present disclosure, the transmission rod 405 is sleeved in the ring 402 of the tail end of the piston. An outer diameter of the transmission rod 405 is smaller than an inner diameter of the ring 402 so that the transmission rod 405 has a rotation area so as to reduce the influence on the displacement of the piston's movement path. The transmission rod 405 pushes and pulls the piston to make linear sliding.

A frame 401 is arranged in the housing 100 for supporting the transmission assembly. The gear plate 410 is supported by the frame.

The gear plate 410 has an external teeth provided on the outer periphery of the gear plate 410. The motor 400 has a shaft with a transmission gear, the gear plate 410 meshes with the transmission gear of the motor 400.

The communicating pipe 300 includes a first pipe section connected with the inflating tube and a second pipe section connected with the inlet tube 203, and the first pipe section is connected to the second pipe section. In this way, it is convenient to assemble, and facilitate subsequent maintenance, etc. The one-way valve 500 may be arranged in the first pipe section or the second pipe section, depending on actual needs.

the tail end of the piston has a hole provided in the central area of the tail end, and the transmission rod is at least partially sleeved in the hole.

Referring to FIGS. 7-8, two power supplies and two power supply protection units are shown. In fact, the two power supply units may be one same power supply unit 31, and the two power supply protection units are one same power supply protection unit 34.

In the embodiment, the controller 800 includes a controlling circuit for controlling the operating state of the air pump. The controlling circuit includes a power supply 31, a controlling unit 32, two selecting switches 331 and 332, a power protection unit 34, and an inflation speed controlling unit 35 and a power switch 36.

The power supply 31 is used to provide working power for each unit. The power supply 31 may convert the live wire voltage in the power grid into the working voltage required by each circuit after step-down rectification and filtering, or it may be a DC voltage source such as a 6-volt power source.

Each of the two selecting switches 331 and 332 has an input terminal connected with the power supply, an output terminal connected with the air pump, a ground terminal, and a controlling terminal connected with the controlling unit 32. The selecting switch includes a connecting terminal connected to the air pump, and the connecting terminal of the selecting switch is selectively connected to the input terminal or the ground terminal of the selecting switch according to an selecting signal from the controlling unit 32.

The controlling unit 32 is configured to output a selecting signal to the selecting switches 331 and 332, so that the output terminals of the selecting switches 331 and 332 are selectively connected to the input terminal or connected or disconnected to the ground terminal.

During the air pump is working, a coil of the air pump will generate a reverse voltage, and the reverse voltage may damage the power supply 31. A power protection unit 34 is arranged between the power supply 31 and the air pump to protect the power supply 31. The power supply protection unit 34 is directly connected between the power supply 31 and the air pump.

The inflation speed controlling unit 35 controls the inflation speed of the air pump by controlling the time for the current to flow through the air pump. Therefore, the inflation speed controlling unit 35 is provided at a position capable of turning on or off the current path of the air pump. For example, the inflation speed controlling unit 35 is arranged between the ground terminals and the ground terminals of the selecting switches 331 and 332, or arranged between the power supply unit 31 and the input terminals of the selecting switches 331 and 332, or arranged between the air pump and the two selecting switches 331 and 332.

The power switch 36 is used to control the on-off of the air pump controlling circuit and the power source, and is equivalent to the main power switch.

The power supply 31 includes a power, a first resistor R1, a second resistor R2, a switch K1, and a voltage stabilizing module.

The controlling unit 32 includes a D-type flip-flop, a first transistor Q1, a second transistor Q2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.

The selecting switches 331 and 332 include a first P-channel depletion type field effect transistor, which is defined as a first field effect transistor T1, and a second P-channel depletion type field effect transistor which is referred to as a fourth field effect transistor T4, a first N-channel depletion type field effect transistor which is defined as a second field effect transistor T2, and a second N-channel depletion type field effect transistor which is defined as third field effect transistor T3. The first field effect transistor T1 and the second field effect transistor T2 constitute a first selecting switch 331. The third field effect transistor T3 and the fourth field effect transistor T4 constitute a second selecting switch 332.

The power protection unit 34 includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, and a first capacitor C1.

The inflation speed controlling unit 35 includes a seventh resistor R7, an eighth resistor R8, a second capacitor C2, and a fifth field effect transistor T5.

The power switch 36 includes a ninth resistor R9 and a sixth field effect transistor T6.

The connection relationship of the electronic components in the power supply 31, the controlling unit 32, the selecting switches 331 and 332, the power protection unit 34, the inflation speed controlling unit 35, and the power switch 36 may be described below.

The power supply 31 is a +6V power, and may also be another DC power supply greater than +6V. The power source is connected to the input terminal Vin of the voltage stabilizing module after passing through the first resistor R1. After the second resistor R2 and the switch K1 are connected in series, the opposite end of the second resistor R2 and the switch K1 and the opposite end of the switch K1 and the second resistor R2 are respectively connected to the input terminal Vin and the output terminal Vout of the voltage stabilizing module. That is, the second resistor R2 and the switch K1 are connected in series and connected in parallel with the voltage stabilizing module. The second resistor R2 is a short-circuit resistor. When the voltage of the power supply is greater than the voltage required by the air pump, the switch K1 is turned off, and the voltage from the power supply is reduced by the voltage regulator module to provide voltage for the air pump and other electronic components that need to be powered. When the voltage of the power supply 31 is equal to the voltage required by the air pump, the switch K1 is turned on, and the voltage from the power supply can directly provide voltage to the air pump and other electronic components that need to be powered via the second resistor R2. This means of directly supplying power by the second resistor R2 can reduce the loss of electric energy by the voltage stabilizing module, thereby improving the efficiency of the power supply. The voltage stabilizing module in this embodiment may use the voltage stabiliser 1117-3.3V of AMS Company.

In the selecting switches 331 and 332, the drains of the first FET T1 and the second FET T2 are connected as the output terminal of the first selecting switch 331, which is connected to the first terminal 1 of the air pump. The drains of the third field effect transistor T3 and the fourth field effect transistor T4 are connected as the output end of the second selecting switch 332, which is connected to the second terminal 2 of the air pump. The sources of the first field effect transistor T1 and the fourth field effect transistor T4 are respectively used as the input terminals of the first selecting switch 331 and the second selecting switch 332, which are connected to the output terminal Vout of the voltage stabilizing module. The sources of the second field effect transistor T2 and the third field effect transistor T3 serve as the ground terminals of the first selecting switch 331 and the second selecting switch 332, respectively, and are connected to the source of the fifth field effect transistor T5. The gates of the first field effect transistor T1 and the second field effect transistor T2 are connected as the controlling terminal of the first selecting switch 331. The gates of the third field effect transistor T3 and the fourth field effect transistor T4 are connected as the controlling terminal of the second selecting switch 332.

In the controlling unit 32, the base of the first transistor Q1 is connected to the Q output terminal of the D flip-flop through the sixth resistor R6. The collector of the first transistor Q1 is connected to the grids of the third field effect transistor T3 and the fourth field effect transistor T4. At the same time, the fifth resistor R5 is connected to the output terminal Vout of the voltage stabilizing module. The emitter of the first transistor Q1 is connected to the housing of the electronic blood pressure monitor. The base of the second transistor Q2 is connected to the output terminal Q of the D flip-flop through the fourth resistor R4. The collector of the second transistor Q2 is connected to the gates of the first field effect transistor T1 and the second field effect transistor T2. At the same time, the third resistor R3 is connected to the output terminal Vout of the voltage stabilizing module, and the emitter of the second transistor Q2 is electrically connected to the housing 100.

In the power protection unit 34, the cathode of the first diode D1 and the anode of the second diode D2 are connected to the first terminal 1 of the air pump. The cathode of the third diode D3 and the anode of the fourth diode D4 are connected to the second terminal 2 of the air pump. The anodes of the first diode D1 and the third diode D3 are electrically connected to the housing. The cathodes of the second diode D2 and the fourth diode D4 are connected to the output terminal Vout of the voltage stabilizing module. At the same time, it is electrically connected to the casing through the first capacitor C1.

In the inflation speed controlling unit 35, the gate of the fifth field effect transistor T5 is connected to the TXAO output terminal (not shown in figure) of the first microcontroller through the seventh resistor R7 and the eighth resistor R8. The speed controlling signal unit in the first microcontroller outputs a speed controlling signal. The source of the fifth field effect transistor T5 is connected to the source of the third field effect transistor Q3, and the drain of the fifth field effect transistor T5 is connected to the source of the sixth field effect transistor T6. One end of the second capacitor C2 is connected to one end of the seventh resistor R7 and the eighth resistor R8, and the other end of the second capacitor C2 is connected to the source of the fifth field effect transistor T5. During use, the first microcontroller outputs a PWM modulation wave to the fifth FET T5. The second capacitor C2 removes a noise signal from the first microcontroller, and avoid affecting the on or off time of the fifth FET T5 due to noise in the circuit, so as to better control the inflation speed of the air pump.

The gate of the sixth field effect transistor T6 in the power switch 36 is connected to the PUMPC output terminal (not shown in the figure) of the first microcontroller through a ninth resistor R9. The power controlling unit in the first microcontroller outputs a signal to turn on or off the power. The source of the sixth field effect transistor T6 is connected to the drain of the fifth field effect transistor T5, and the drain of the sixth field effect transistor T6 is connected to the housing.

While the present disclosure has been described with reference to a specific embodiment, the description of the disclosure is illustrative and is not to be construed as limiting the disclosure. Various of modifications to the present disclosure can be made to the exemplary embodiment by those skilled in the art without departing from the true spirit and scope of the disclosure as defined by the appended claims. 

1. A fast inflating air pump comprising: a housing including an upper shell and a lower shell; an inflating tube including an inflating port exposed on the outside of the housing, an inlet tube including an inlet port exposed on the outside of the housing for communicating with external air, a communicating pipe arranged between the inflating tube and the inlet tube for communicating with each other, a motor, a transmission assembly and a controller; and wherein a blower is arranged in the inlet tube for increasing air pressure to the inflating port; a piston is at least partially contained in the inflating tube, the piston is driven by the motor via the transmission assembly so as to slide back and forth linearly for increasing air pressure in inflating tube; a one-way valve is installed in the communicating pipe for only allowing air flow into the inflating tube; the controller instructs the blower to work until an air inflation pressure reaches a predetermined threshold, then the controller instructs the blower to stop working; the controller instructs the motor to drive the piston to slide back and forth in the inflation tube on condition that the blower stops working until the air inflation pressure increases to another predetermined threshold, then the controller instructs the motor to stop operating.
 2. The fast inflating air pump as described in claim 1, wherein the inflating tube includes a small-diameter section and a large-diameter section extending from the small-diameter section, a diameter of the large-diameter section larger than that of the small-diameter section, the inflation port is formed in the small-diameter section and the piston movably slides in the large diameter section of the inflating tube.
 3. The fast inflating air pump as described in claim 1, wherein the piston includes a head end, a tail end and a piston rod between the head end and the tail end.
 4. The fast inflating air pump as described in claim 3, wherein the transmission assembly includes a gear plate driven by the motor, an eccentric wheel, a rotating shaft located in the centre of the gear plate and connected to the eccentric wheel, and a transmission rod located on the eccentric wheel for connecting with the piston.
 5. The fast inflating air pump as described in claim 4, wherein the gear plate drives the eccentric wheel to rotate via the rotating shaft, and the eccentric wheel pushes or pulls the piston to slide via the transmission rod.
 6. The fast inflating air pump as described in claim 4, wherein the tail end of the piston includes a ring and a hole provided on the ring, and the transmission rod is sleeved in the ring.
 7. The fast inflating air pump as described in claim 4, wherein the gear plate has an external teeth provided on the outer periphery of the gear plate, the motor has a shaft with a transmission gear, and the external teeth of the gear plate meshes with the transmission gear of the motor.
 8. The fast inflating air pump as described in claim 4, wherein a valve plate mounted in the inflating tube is located above the head end of the piston for allowing air flow into the inflating port of the inflating tube only.
 9. The fast inflating air pump as described in claim 8, wherein the valve plate includes a rigid sheet with a plurality of holes, and a rubber sheet is attached to the rigid sheet for blocking the plurality of holes of the rigid sheet.
 10. The fast inflating air pump as described in claim 8, wherein the head end of the piston is in shape of a disc with a plurality of holes, and a damper is mounted on the head end and covers the plurality of holes of the head end.
 11. The fast inflating air pump as described in claim 10, wherein the head end further has an upper flange on the periphery of the disc, an upper flange on the periphery of the disc and a ring groove between the upper flange and the lower flange for mounting the damper.
 12. The fast inflating air pump as described in claim 11, wherein the damper has a central part for covering the he plurality of holes of the head end, two bridges extending from the central part along a direction far away each other, and an annular wall located on the outer peripheral side of the two bridges and connected to the two bridges.
 13. The fast inflating air pump as described in claim 12, wherein the annular wall has an inner wall extending from the two bridges, an outer wall extending from the inner wall and a groove provided between the inner wall and the outer wall.
 14. The fast inflating air pump as described in claim 12, wherein two notches are provided on the upper flange of the head end of the piston for matching the two bridges of the damper, respectively.
 15. The fast inflating air pump as described in claim 10, wherein an air chamber is formed by the valve plate, the head end with the damper and a part of the large-diameter section of the inflating tube.
 16. The fast inflating air pump as described in claim 1, wherein the controller is provided with a controlling circuit for controlling the operation of the air pump, and includes a power supply, a power switch, a controlling unit and two selecting switches, each of the two selecting switches has an input terminal connected with the power supply, an output terminal connected with the air pump, a ground terminal, and a controlling terminal connected with the controlling unit, the selecting switch includes a connecting terminal connected to the air pump, and the connecting terminal of the selecting switch is selectively connected to the input terminal or the ground terminal of the selecting switch according to an selecting signal from the controlling unit.
 17. The fast inflating air pump as described in claim 16, wherein each of the two selecting switches includes two field effect transistors with different conduction potentials, the two field effect transistors define a first field effect transistor and a second field effect transistor, a source or a drain of the first field effect transistor severed as the input terminal of the selecting switch, the drain or source of the first field effect transistor connected to a source or a drain of the second field effect transistor as the output terminal of the selecting switch, the drain or the source of the second field effect transistor served as the ground terminal of the selecting switch, a grids of the two field effect transistors connected as the controlling terminal of the selecting switch.
 18. The fast inflating air pump as described in claim 17, wherein the two field effect transistors are defined an N-channel field effect transistor or a P-channel field effect transistor.
 19. The fast inflating air pump as described in claim 18, wherein the controller includes a flip-flop and two triodes, a base of the two triodes are respectively connected to two output terminals of the flip-flop, a collector of the two triodes are respectively connected to the controlling terminals of the two selecting switches, and a emitter of the two triodes connected with the ground respectively, the flip-flop outputs a high and a low-level signal to make one of the two triodes turn on, and the other turns off. 